Valve Spring - Broken problem found

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DemonK9

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Had time today to dig into the non-combustion issue on cylinder #2.....did a compression test, came up 0, as I thought it may have.....but hoping it wasn't a dead hole (ring problem).
Took valve cover off and this is what I found....just laying there, and then the spring on the forward-most valve (This would be the valve train rattle, I was hearing....lol). Is this the intake or exhaust valve???


20190608_160527.png


20190608_160546.png
 
Had time today to dig into the non-combustion issue on cylinder #2.....did a compression test, came up 0, as I thought it may have.....but hoping it wasn't a dead hole (ring problem).
Took valve cover off and this is what I found....just laying there, and then the spring on the forward-most valve (This would be the valve train rattle, I was hearing....lol). Is this the intake or exhaust valve???

View attachment 1715346716

View attachment 1715346718


Oops! Good that you found it. Hopefully no other damage.
 
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Looks like number 2 exhaust. I'd pull every spring off and throw them in the garbage. There is no reason for a spring like that to fail like that.

Those are J U N K junk.
 
Had time today to dig into the non-combustion issue on cylinder #2.....did a compression test, came up 0, as I thought it may have.....but hoping it wasn't a dead hole (ring problem).
Took valve cover off and this is what I found....just laying there, and then the spring on the forward-most valve (This would be the valve train rattle, I was hearing....lol). Is this the intake or exhaust valve???


View attachment 1715346716

View attachment 1715346718

Exhaust
 
So now what comes next? That valve has likely been tapping on the piston and may be bent!
The piece of "debris" used to be a spring shim (not made out of hardened steel). Do you have a way of testing cylinder sealing?
How far from Swift Current are you?
 
So now what comes next? That valve has likely been tapping on the piston and may be bent!
The piece of "debris" used to be a spring shim (not made out of hardened steel). Do you have a way of testing cylinder sealing?
How far from Swift Current are you?
Pull the head off
 
So now what comes next? That valve has likely been tapping on the piston and may be bent!
The piece of "debris" used to be a spring shim (not made out of hardened steel). Do you have a way of testing cylinder sealing?
How far from Swift Current are you?
Going to have to pull the head off and see what kind of Tomfoolery and damage has happened. No way of testing cylinder sealing, but I think that is erroneous, since the heads got to come off.
I am about 3 hrs strait north from Swift..........why, do you have some nice rebuilt heads for sale for a 340? LOL

Pull the head off

Will have to do that when I get time.........busy time of year for me, so not sure when that will happen.
Should a guy rebuild the whole head with new parts while it is off or just fix what is broken? This car is with me for life, but I didn't want to dive into a motor rebuild/performance build yet. Should I just slap on some new heads and be done with it and the worrying if more of this head is going to fail or the other head fail as well???
 
Looks like number 2 exhaust. I'd pull every spring off and throw them in the garbage. There is no reason for a spring like that to fail like that.

Those are J U N K junk.

Ya, I am far from an engine master....I have done motor swaps/replaced heads/timing chains/hedders, etc. I know my way around an engine and not afraid to get at it with older cars that are simple......when i seen that spring, I thought it was odd, since it does a simple task and shouldn't break like that.......but I lack the knowledge and experience to know what is and isn't junk in a head....lol.
Thanks for your input calling them junk, it now leans me towards replacing the heads, getting rebuilt ones or getting these rebuilt with quality parts.
 
Ya, I am far from an engine master....I have done motor swaps/replaced heads/timing chains/hedders, etc. I know my way around an engine and not afraid to get at it with older cars that are simple......when i seen that spring, I thought it was odd, since it does a simple task and shouldn't break like that.......but I lack the knowledge and experience to know what is and isn't junk in a head....lol.
Thanks for your input calling them junk, it now leans me towards replacing the heads, getting rebuilt ones or getting these rebuilt with quality parts.


I don't think the heads are junk, just the spring.

When you see a spring fail like that, in an application such as yours, that's just a junk spring. I've done that to some very good springs, but that was at 8500 so it's a bit more acceptable. Not much, but a bit more. At least you can say at that RPM the spring has a short service life.

In your case, that spring should have went a 100k and never missed a beat.
 
I don't think the heads are junk, just the spring.

When you see a spring fail like that, in an application such as yours, that's just a junk spring. I've done that to some very good springs, but that was at 8500 so it's a bit more acceptable. Not much, but a bit more. At least you can say at that RPM the spring has a short service life.

In your case, that spring should have went a 100k and never missed a beat.

I was agreeing with you about the springs being junk....it was maybe my wording that seemed like the heads were junk as well......no problem, it's all good.
I honestly appreciate the candid feedback.....my feelings rarely get hurt, no worries there....lol....no need to beat around the bush.....junk is junk.

No question these heads have to be pulled and upgraded with some quality parts now, to get it back to a normal driver for now.
 
Just my 2 cents.
Other than metal in the oil. You could replace the valve spring on the effected cyl and do a compression test and see what happens. Some day you will rebuild it.
You will know if the valve is bent.

If the compression is good replace the rest of the springs to be on the safe side
 
In the video I can't clearly see the valve tip, but I think that tip appeared to be chewed up. Post a picture of the valve tip and also a picture of the rocker arm tip that was riding on that valve.
 
Just my 2 cents.
Other than metal in the oil. You could replace the valve spring on the effected cyl and do a compression test and see what happens. Some day you will rebuild it.
You will know if the valve is bent.

If the compression is good replace the rest of the springs to be on the safe side
Yes, you will know the if the valve is bent.... especially if you do a leakdown test. The spring can break and the valve not hang very far into the cylinder. You can make a judgement of how far just by laying a straight edge across the other retainers and this one
 
Crane part # 69308 spring & retainer kit. I used this on my 360. Haven't fired it yet not sure how good they are but look like a quality part. Anybody use these? Good or bad experience?
 
I've had a few valves spanked by the piston for misc. reasons.

Mosta them were fine.

Replace the failed part, compression test, - as mentioned, retainer height maybe an indicator, if all other retainers are level .
 
I finally had time today to go wrench on the 340 head. I didn't pull the head and used the old rope in cylinder trick to hold the valves up, so I could change out the springs in cylinder #2. Swapped out both springs for that cylinder with the Melling vs-1120 springs. The rocker and valve tip were fine, not all chewed up.
Put it all back together and it has gone from running like an old grain truck to running like a champ........smoke, rubber and sideways through 1st & 2nd :lol:

I would like to get a 2nd set of heads right away, rebuild them and slap them on though, for peace of mind that other springs are not going to fail. I think Edelbrock heads are overkill, until I decide to rebuild the entire motor.
What are some good quality parts to rebuild cylinder heads with?
-The Crane part # 69308 spring & retainer kit should be a quality part, but what about rockers and all the rest going on the head? Any suggestions?

Thanks in advance
 
not knowing what your cam is
if you are not pushing the envelope get your springs from Elgin or similar
CRANE does not make springs (and who are they since they moved?)
340 springs should work for most lower lift HFT's
set of new viton stem seals while you are at it
you can do a leak down test or even check the compression on that hole
wait till you get a new higher liift cam that actually requires new springs
and the heads off to do the spring seats and guides
rockers ok- if it aint broke don't fix it
save your money cuz I'd check the timing chain
 
I finally had time today to go wrench on the 340 head. I didn't pull the head and used the old rope in cylinder trick to hold the valves up, so I could change out the springs in cylinder #2. Swapped out both springs for that cylinder with the Melling vs-1120 springs. The rocker and valve tip were fine, not all chewed up.
Put it all back together and it has gone from running like an old grain truck to running like a champ........smoke, rubber and sideways through 1st & 2nd :lol:

I would like to get a 2nd set of heads right away, rebuild them and slap them on though, for peace of mind that other springs are not going to fail. I think Edelbrock heads are overkill, until I decide to rebuild the entire motor.
What are some good quality parts to rebuild cylinder heads with?
-The Crane part # 69308 spring & retainer kit should be a quality part, but what about rockers and all the rest going on the head? Any suggestions?

Thanks in advance
I used the crane sprinh and retainer set. Looks very well made. Bought from a member. Haven't fired motor yet. But crackedback has used this spring set before and says they worked good.
 
Looking at the intake valve, the retainer looks small for the spring. Before you pull the head put some air pressure in that cylinder, pull up on the valve and see if it seals.
 
Good deal OP! Those springs are the standard Crane catalog HFT spring set: singles with moderately high rate (386 lb/in) , stronger than the stock 340 springs. Up to .500" lift. So what I would think of as 'medium' performance use in this day and age.
 
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